Description:Refraction of sun light due to cold dense polar air under warmer thermal layers causes an increase in brightness almost unknown within present physics literature. Global Warming may be seen by studying simple satellite picture archives. Low on the horizon polar sunsets have sun disks compressed into a line. Thermal Inversions cause equally an increase in brightness during twilight.

This page contains a vast database pertaining to temperate and polar sunsets. It also holds many differential refraction pictures, at multiple Zenith Angles. Recently conceived twilight brightness theory with respect to the Y-V Ulluq Q effects are presented. Extraordinary Moon shots show simple refraction. The data is there for you to study, the thoughts are progressive from February 2001 till today, they change according to knowledge acquired from this page and from other pages as referred to below. The data presented is quite accurate, calculations if any can be verified, while past thought mistakes are left untouched, in order to leave the examiner review a fascinating journey in science. Major paradigm shifts will be explained on each individual pages, they will be recognizable by the date they are written.

WD, December 2004

Atmospheric Refraction is very misunderstood or rather under-studied, it has enormous potential to solve apparently complex problems, like the true temperature of the troposphere. A landmark paper:
SUNSET SCIENCE. IV. Low-altitude refraction. By Andrew T. Young, Departnment of Astronomy, San Diego State University, Astronomical Journal, 127:3622-3637, 2004 June.

Proves without much doubt that Astronomical refraction is caused in the Troposphere. This certain fact can help ascertain key measurements, as used on this webpage, helping to calculate the temperature of the lower troposphere, without MSU doubts, such as radiometer microwave satellite readings which fail to distinguish the Stratosphere from the Troposphere.

Another important paper has shown the sun seen by explorers in 1597 at -5.7 degrees below the horizon. This record still holds to this date:

~There is also some unfamiliar gyrations or lack thereof of the sea ice horizon

What is sea ice first melt? Best explained by observations:

March 9 2013, a diurnal variation of the sea ice horizon. This is newly formed first year sea ice from the worse melt in sea ice history in 2012. At left the horizon was lowest, following sun ray bombardment at local apparent noon, this happens when the thermal structure of the sea surface to air interface has an isothermal structure. the air immediately above the ice has a lapse rate nearing 0 degrees C/km. As the evening approached concurrently with the lower sun elevation something not
immediately obvious happens, the horizon rose( middle) by a very significant 1.3' (minutes of arc), this would be if the sea ice physically rose 18.6 meters 40 kilometers away. At sunset (right picture) the horizon didn't rise much further in fact dropped a bit, this means the ice was not so thick. The sea ice core temperature could be very much colder, 11' of arc horizon boost was measured once in the same location.

Sea ice core temperature is an important player in sea ice horizons. Thermodynamically, with lab conditions, air cools faster than ice (in a dark place, like a cloudless night), when not warmed by sun rays, this would lower the horizon if so. But the ice usually has a significantly colder core than its surface warmed by solar radiation. This core cools the noon warmed sea ice surface faster than the air, which in turn cools the interface air faster than the layer of air just above it. A colder layer of air under a warmer one is called an inversion. An observer can "see" this inversion by studying the horizon.

A very old sea ice pan, say 10 meters thick, has a colder core temperature even outlasting the Arctic summer (the ice survives!), thicker sea ice can have much colder core temperature, and conversely, the horizon may rise. The opposite is so, the thinner the sea ice , the warmer the core and the lesser the horizon shift:

March 9 2016, the sea ice horizon did not move despite partially sunny conditions (3' of arc), and some haze, the same thing happened on sunny March 7. Therefore , this is first melt conditions. Whereas the horizon like this has not been measured since there was open water last September and or thin sea ice last October .

First melt in early March?

Repeatable horizon measurements at the same altitude as when open water temperatures was equal to the air is the definition of the first melt, When so, accretion stops, and the bottom may melt since sea water is as warm as bottom salty sea ice.

2015 first melt was March 26, 2014 April 10, 2013 March 23, 2012 March 17, 2011 April 15 and 2010 March 19.

Implications

Without a doubt 2016 has the thinnest ice, thinner than 2012. And the sea ice causing the least variations in March, the coldest historical sea ice period. If there is no massive cooling about, this thinner sea ice means earliest arrival of melt ponds with earliest break ups all over the Arctic. If we follow the South Cornwallis Island record carefully, the second earliest first melt year was 2012

WD March 9, 2016

2016 Arctic sea ice thickness may be thinnest in history?

~Satellite sensors and refraction method match results

~On a wider scale 2016 is heading towards a furtherance of all time melt records

After 2012 super synergistic melt. Arctic sea ice looked doomed. But the last thing most experts forgot, the one reason why 2012 sea ice melted so much was that all the weather elements were inclined to do so. Compaction was nearly as ideal as 2007, clouds and cyclones were scarce, along with clear blue 24 hour solar ray melting. The once thick expansive mighty multi-year ice pack was limited to a thin sliver of the NW Arctic Archipelago coast. And so it looked like the next few years we should have seen a whole lot of less sea ice. That wasn't so, not because weather varies from summer to summer, but especially, ironically, it takes thick sea ice to create summer Arctic dipoles creating great compactions. The next few melt seasons were lesser, because there was far lesser compaction and much more clouds (cooling) especially from ever so persistent summer cyclones over the Arctic Ocean.

Despite very poor summer insolation seasons for 2013,2014 and to a lesser extent for 2015.
Sea ice thickness early February 2016 appears significantly diminished everywhere in the Arctic but for near the North Pole. The reason why PIOMAS appears to indicate much more over all sea ice thickness is a mystery to me. The US Navy seems to have a better grasp on the measure of things.

"Mystery Beneath the ice" was about plummeting krill stocks in Antarctica.

But they reiterated a huge problem with sea ice, its not uniformly stratified on its surface or bottom.

The way to measure sea ice thickness over its entire region may be very complex, and definitely requires satellites with resolution capacities approaching 1 meter. But there is another way, horizon refraction measurements capture the lapse rate of the sea ice to air interface instantly, ultimately simplifying the effort of measuring things meter by meter. Instead an horizon photograph encapsulates the actual over all thickness of the sea ice as well as the temperature of its air right above, over a huge area at once.

Now let us compare the US NAVY with horizon refraction method:

February 6 2013, the sun just appeared, but its rays penetrate many equivalent atmospheres, its effect was still felt further to the South, and a layer of warm air spread Northwards. Depending on how thick the ice is, the sea ice horizon will vary in height. The thinner the ice, the weaker the inversion lapse rate immediately above, the lesser the horizon rises. Right after the great melt of 2012 the sea ice of the Northwest Passage from Southwest Cornwallis Island appeared thin.

February 6 2016, the Northwest passage sea ice appears thinner, each line 3.3' of arc.
The shallowest of horizon height gains ever for this time of the year. It is almost first melt time a full 40 days before the earliest day observed.

These zoomed sections of the top maps above (February 6 2013 (left), from center to right is the same area on February 6 2016 . Cornwallis Island is seen second island from the extreme left where the thin line is the observation ray path from land towards the left (the NorthWest passage). 2013 had thicker sea ice, 2016 much thinner. Likewise the ice horizon of February 6 2013 was higher than same day in 2016.

Although there is still a lot of sea ice, this years outlook is very bleak. The only thing stopping a further expansive melt are clouds and the positioning of cyclones during the summer season.

According to NASA 2015 Northern Hemisphere January to December average was +0.22 C greater than 2014 during the same period. A staggering near 20% jump. El-Nino's influence can be read at year end. The beginning of the year was likely more at the state of warming already in Earth's atmosphere. The other warmest El-Nino was 1998:
1998 66 105 71 88 67 74 78 74 62 56 59 79 73 71 75 75 75 59 1998

"Because of overwhelming refraction heat signals, 2015 will be warmest year in Northern Hemisphere history - by a significantly larger margin than 2014. No High Arctic observations over Cornwallis Island gave a consistent sign of cooling, despite being right near center of coldest atmosphere in the world. This forecast is not at all counting on El-Nino rising again, which undoubtedly guaranties more heat."

The writing of 2015 warming was in sun disks well before year end. However, refraction prognosis methods are not only to be found with astronomical objects. 2016 is already significantly warmer than 2015 by another way to judge the warmth of the planet...... With sea ice. More on this soon.

WD January 20 , 2016

In total darkness Mid-winter Record shattering heat surge over the Arctic Ocean

~There were Cyclonic incursions in the past , but there was more sea ice thickness

~There is no sun over the Arctic yet we witness no "IRIS" effect when the planet is at its warmest

First we look back to late 1980 when the multi-year ice was very thick:

It was a warm Christmas over Siberia in 1980, much warmer than over the Canadian Arctic.
600 mb temperatures courtesy NOAA are very close to the Density Weighted Temperature (DWT) of the entire troposphere. Temperature picture December 26 (left) was not much different compared to December 29 (right), The Polar region in total darkness coldest air morphed a bit but everywhere temperatures of the entire atmosphere was colder than -20 C while in the Canadian Arctic as cold as -40 C almost all the way to the North Pole. DWT 's clearly show the center of the Polar vortex, where all Northern Hemisphere circulation driving winds turn counterclockwise around it.

El-Nino 1998 was strongest, likely stronger than 2015 to date, already we see the circulation pattern markedly different same December 26-29 comparison with 1980. Note the beginning of a Cyclone affecting the DW

Temperature profile of the atmosphere about Iceland on December 29.

In 1998 the sea ice started to decline in thickness and extent. Its a marking year. Winter was still
strong during the holiday season. Day to day variations of DWT's were very reasonably predictable and not dramatic.

El-Nino 2015 is similar to 1998, except for a larger warmer sea temperature anomalies for the North Pacific. Yet December 26-29 DWT image is staggeringly different, as well as sea ice thickness and extent:

The gradual but rapid decrease in sea ice thickness since 1998 has had a major playing role decreasing the build up to winter.

From December 26 to 29 2015, the entire Arctic atmosphere significantly warmed in total darkness! An important Low pressure system, one following many, easily penetrated the North Pole region which had DWT temperatures usually close to -40 C, now more like -8 C, again this is the temperature of the entire atmosphere not just the surface, in the past not changing fast in a matter of days. In total -no sun - darkness the usual pattern was stable DWT's. Another marked feature of current 2015-16 season is this darkness warming, never readily noticeable in the past, as winter progresses it usually gets colder not warmer! Now we noticed with ease warming bursts at least 3 times since November 2015. The Cold Temperature North Pole (CTNP) and Arctic has warmed significantly since 1998. This allows Cyclones to penetrate a weakened state of winter which is made in great part in the Arctic, this affects weather world wide. But now, this is new, we witness temperature warming surges causing incredible dynamic changes undoubtedly which will continue to cause tremendously different weather scenarios, some good for warm temperature lovers, but will cause many severe stressful events for human infrastructures as much as on all ecosystems.

Siebren van der Werf, from Holland, has finally a webpage including down loadable Journal links, also with programs capable of calculating sundisk sizes, along with sunset and sunrise shapes with a great deal of accuracy. He is one of the few top notch refraction expert of this world. Reading his material will make you nearly up to date with the latest cutting edge knowledge, including differential formulas, his works are required reading.

Ben Wheeler and Ethan Sollows.

Andrew T. Young's web page "An Introduction to Green Flashes" is essential to understand other refraction effects near the horizon. Dr. Young puts to rest many misconceptions which are still ingrained everywhere.

On his way to the North Pole, Gunther Kletetschka, a physicist, gave me a hand, pictures from his adventure can be foundhere.

Other related links:

Very important sunset sequences can be found at Tom Ruen 's web page. He's a Lake Superior expert on this subject. Some pictures resemble polar pictures, proving that Lake Superior is a cold lake indeed.

Zoltan Neda and other wrote 2 papers on the subject of sun flatness. Great pictures from space show a fantastic resemblance to pictures taken from Resolute Bay.

Stonehenge Then: Many of the sun disk transformations found on this web page ressemble Megalithic structures found throughout the UK, Ireland and Northwestern Europe. Stonehenge Then is a web page designed to recruit more research in horizon observations at Megalith sites. It contains many theories which need field workers to confirm. These theories need to be checked out by hopefully volunteers, or eventually myself.